Having problems with nat

[Cyndre]

Im having massive lost packets and slow internet connections. I just put the router in place and configured it yesterday, and I have had nothing but problems please help. If you need more information then what I am giving you, please dont be afraid to ask for it.

interface Ethernet0/0
description connected to Internet
ip address 204.50.48.153 255.255.255.240
no ip directed-broadcast
ip nat outside
!
interface Ethernet1/0
description connected to EthernetLAN
ip address 192.168.1.1 255.255.255.0
no ip directed-broadcast
ip nat inside
!
interface Ethernet1/1
no ip address
no ip directed-broadcast
shutdown
!
interface Ethernet1/2
no ip address
no ip directed-broadcast
shutdown
!
interface Ethernet1/3
no ip address
no ip directed-broadcast
shutdown
!
router rip
version 2
passive-interface Ethernet0/0
network 192.168.1.0
no auto-summary
!
ip nat pool Psychic-Doom-natpool-1 204.50.48.146 204.50.48.152 netmask 255.255.255.240
ip nat inside source list 1 pool Psychic-Doom-natpool-1 overload
ip nat inside source static 192.168.1.105 204.50.48.148
ip nat inside source static 192.168.1.103 204.50.48.152
ip nat inside source static 192.168.1.102 204.50.48.147
ip nat inside source static 192.168.1.101 204.50.48.146
ip classless
ip route 0.0.0.0 0.0.0.0 Ethernet0/0
ip http server
!
access-list 1 permit 192.168.1.0 0.0.0.255
access-list 101 deny ip host 204.50.48.146 any
access-list 101 permit tcp any any established
access-list 101 permit tcp any host 204.50.48.146 eq 44405
access-list 101 permit tcp any host 204.50.48.146 eq 55901
access-list 101 permit tcp any host 204.50.48.146 eq www
!
line con 0
exec-timeout 0 0

Now the problem is with the forwarding of the ports, its using 90% of my router and everything is of course slow, and over half my normal users cant connect.